Crypts of Chaos was an early example of a "3-D" dungeon crawl game, clearly designed to capitalize on the D&D fad of the day. Produced by 20th Century Fox, it wasn't an "official" Atari game, which, with the exception of the games made by Activision, pretty much ensured it would be awful -- and Crypts of Chaos was. Even by the graphical standards of the day, it was ugly, confusing, and difficult to play. The eponymous Crypts were (literally) a maze of corridors and rooms and players were advised to make a map of the place as they explored it to avoid getting lost. Along the way, you'd encounter badly-pixelated monsters who might have treasure that would be of use in trying to survive through the unending slog of this game.